Smaller dog would fit better. Large dogs are often not welcome renting and at some hotels. Also if you need to fly, the larger the dog the harder it is.

As for travelling, the right dog will handle it in stride.

I would look at smaller confident out going athletic little dogs. The joy of adopting an adult is you will have an idea if the dog has the right temperament to deal with your life style. I had a JRT who would have killed to be your dog

As for quarantine. You can go to the UK sans quarantine if you meet their requirements and are coming from an EU or approved (which is most first world nations and then some). There are a few places you can't go with out quarantine. Iceland, Australia and Hawaii I believe.